1. Field of the Invention
The present invention relates to a charge controlling circuit. More specifically, the present invention relates to a charge controlling circuit which is applied to a mobile terminal, and controls a charging operation of a secondary battery by an electric power supplied from an external charger.
2. Description of the Related Art
In a general related art of this kind of a circuit, when a mobile terminal having a battery in a fully-charged state is detached from a charger, a timer is activated. When the mobile terminal is connected to the charger again, it is determined whether or not a counted time by the timer is within a predetermined time, and whether or not a battery voltage is equal to or more than a threshold value. If both of the determination results are affirmative, it is determined to be a fully charged state. On the contrary thereto, if at least one of the determination results is negative, recharging the battery is started, and detecting the fully-charged state is performed based on a rate of temperature rise.
However, in the related art, if a detached time during which the mobile terminal having the battery in a fully-charged state is detached from the charger is within the predetermined time, a charging operation (except for small current charging) is not executed, but if the detached time is equal to or more than the predetermined time, a charging operation is executed. In other words, if the mobile terminal having the battery being in a fully-charged state is detached for the predetermined time or more and then attached, again and again, the charging operation is repeatedly executed to cause a deterioration of the battery.